The planet Venus: the Earths twin in a limited sense

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The planet Venus the Earths twin (in a limited
sense)
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Venus in ultraviolet light
What is under The clouds?
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Seeing through the clouds of Venus with Radio
Astronomy!
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The Goldstone (California) tracking station and
planetary radar
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First result light is a wave (electromagnetic
wave)
Wave characterized by wavelength, amplitude DEMO
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Amazing fact of nature wide range of wavelengths
of electromagnetic waves
EM radiation includes gamma rays, x-rays,
ultraviolet, Light, infrared, microwave, radio
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Concept from physics crucial for astronomy the
spectrum of light
DEMO
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The Physics of Spectrum Formation, Kirchoffs
Laws and Wiens Law

• Hot opaque solid or liquid produces a continuous
  spectrum
• Hot, tenuous gas observed against dark background
  produces emission line spectrum
• Cold, tenuous gas observed against bright
  background produces absorption spectrum
• See Figure 16.6

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Kirchoffs Laws of Radiation
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Kirchoffs First Law Wiens Law

• Hot, opaque objects produce continuous spectrum
• The hotter the object, the bluer it is
• Wiens Law wmax 2.9E-03/T
• The hotter an object, the brighter it is